Question about Clutch Delay Valve and launching

sirthanh

sirthanh

Well-Known Member
22
4
Utica, New York
I don't launch my car often, and I never race my car so I'm a novice when it comes to this. Always been scared to damage my car, but I like to do some spirited driving once in awhile.


When I launch my car with my rev limiter set at 3,500 and then fully drop the clutch without feathering and mashing the throttle (i know i know, wheel spin, drivetrain); my car would just quickly speed up to 20mph and stay around there until a second or so AFTER I engaged 2nd gears. Pretty sure it's not because of wheel spin, and if there is any, then it's very minimal spinning. I only did this once or twice, but I was wondering if it's because of our Clutch Delay Valve that is causing the clutch to not engage fully to the engine for harsh launches.

Just double checking to make sure it's the clutch delay valve, and not my clutch going bad. Hopefully it's not, but I'm assuming it can't be my clutch slipping because it operates fine during normal driving or during heavy acceleration without launching. Definitely won't try that type of launch anymore. I will probably just partial throttle next time to get traction.
 
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squiggy said:
What you are feeling is probably the traction control kicking in.
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I had traction control off during the launch.

If it is my clutch slipping under load, then it's a good excuse for me to upgrade my clutch. Finally paid off the car, so I'm probably going turbo next year. :)
 
That was a bit of pertinent information you left out...

Anyway, unless you are over 300whp, your clutch should not be slipping.
 
squiggy said:
That was a bit of pertinent information you left out...

Anyway, unless you are over 300whp, your clutch should not be slipping.
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Forgot to add that in the opening post. Lol

Yeah, I only have bolts on and vit tune atm, so it can't be slipping. Probably just have to work on a better technique for launching.
 
Maybe a better question, would be to ask(those in the know) how to "Do" a proper launch and follow-though......
 
Wheel hop is also a big factor on these cars. Although with stock ish HP you shouldn't be having too big of an issue with that. Launching hard can cause the wheel to hop and bounce and lose traction.
 
Monk said:
Maybe a better question, would be to ask(those in the know) how to "Do" a proper launch and follow-though......
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Every thread on this topic would talk about feathering the clutch during launch. I just hate the idea of easing off the clutch with my RPM shooting way above 4k. Maybe I should just stay away with launching. Haha

Nix said:
Wheel hop is also a big factor on these cars. Although with stock ish HP you shouldn't be having too big of an issue with that. Launching hard can cause the wheel to hop and bounce and lose traction.
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Yeah my car has basically all bolts on and edyno have me at around 195hp, so I can't say it's because of wheel hop. It goes like this

-Drop at 3500
-REV quickly shoots up to 7600 and the car speeds up to around 20mph, but the MPH is not moving on par with REV or that's how I feel. It doesn't feel like the RPM matches my speed.
-Stays there until a half a second or more after I engage second gear then it starts to pick up

So even being in second gear, it's still just revving without moving.
 
I'd have to agree with not doing it at all....... I've never been into doing anything abusive to my car or mc. I'm only into curvy roads.
 
sirthanh said:
Every thread on this topic would talk about feathering the clutch during launch. I just hate the idea of easing off the clutch with my RPM shooting way above 4k. Maybe I should just stay away with launching. Haha



Yeah my car has basically all bolts on and edyno have me at around 195hp, so I can't say it's because of wheel hop. It goes like this

-Drop at 3500
-REV quickly shoots up to 7600 and the car speeds up to around 20mph, but the MPH is not moving on par with REV or that's how I feel. It doesn't feel like the RPM matches my speed.
-Stays there until a half a second or more after I engage second gear then it starts to pick up

So even being in second gear, it's still just revving without moving.
Click to expand...
Have you considered the fact that once you're up past a certain engine speed (RPM) you are out of the power band so the engine doesn't really "pull" any more. You will see the rev's climb but it won't feel like you are going any faster.
That's the key when racing the car, keeping the engine in the max power range at all times.
 
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JonnyRotten said:
Have you considered the fact that once you're up past a certain engine speed (RPM) you are out of the power band so the engine doesn't really "pull" any more. You will see the rev's climb but it won't feel like you are going any faster.
That's the key when racing the car, keeping the engine in the max power range at all times.
Click to expand...

I never complained about the "pull". Wish that was the problem but that isn't the case here. The car should be able to get to 33mp on 1st and 54mph on 2nd.

I can see my RPM shoot to near redline, which is set around 7600 for my car. Even after shifting right before redline, the car won't pick up up until moments after which i strange. It's like the rpm needle shoots up and the car is not moving. Almost like the clutch is slipping.


I'll try to get a video
 
Sounds like a slipping clutch to me if indeed your speed really isn't picking up. You may have glazed your clutch. Are you basing your speed off of the speedometer? Because if you did have wheel spin you'd see your speed shoot way up past how fast you're actually going...
 
Oh, and I don't think it's your clutch delay valve, that delay is very minor. I still have mine in and have no trouble doing burnouts through a 1-2 shift, though I wouldn't recommend doing that often. ;)
 
The clutch delay valve doesnt affect much. If your speedometer and tachometer move independent of each other your clutch is slipping.
 
dath1974 said:
Sounds like a slipping clutch to me if indeed your speed really isn't picking up. You may have glazed your clutch. Are you basing your speed off of the speedometer? Because if you did have wheel spin you'd see your speed shoot way up past how fast you're actually going...
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It's weird. I did it again today, and my tires were actually burning out from 1st to 2nd. It might be because today was A LOT warmer than the other two times I've tried. But when I was burning out, I didn't notice my speedometer shoot up.


Tried the e-brake clutch test and it stalled as it should. Did some heavy acceleration with no launches and it drove just fine.

At this point, I'm going to chalk it up to my stupidity, LOL Maybe the tires were just burning out, but I didn't notice. Honestly I didn't hear them chirp at all, but that's probably because it was 55 degree outside.
 
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